The present invention relates to a method and apparatus for latch hooking on needlepoint-size supports.
In conventional latch hooking, a picture or design is formed on a grid or weave of interlaced threads by securing short lengths of colored twine or rope-like fibrous material such as yarns selectively about the threads that form the grid. The fibrous material commonly employed is of a twisted, multistrand type, each strand being made up of numerous fibrils which may themselves be twisted about one another. Generally, a pattern for the ultimate design is drawn or otherwise imprinted on the grid to serve as a guide for the selective placement of the various colored pieces of yarn or the like.
A latching tool of well-known construction is utilized to attach the lengths of yarn to the grid. Using the tool, a central portion of a length of yarn is looped and passed over a predetermined thread, as indicated by the pattern, and the ends of the piece of yarn are thereafter pulled encirclingly under the thread and through the looped central portion to complete the operation.
The process is sometimes referred to as rug hooking, because while the central portion of the length of yarn is maintained in a wrapped or wound configuration about the thread, its ends extend outwardly from the surface of the grid in the manner of a shag-type carpet or rug. Thus, the ultimate design is formed by a multiplicity of like lengths of yarn of selected colors predeterminately positioned about particular threads on the grid, resembling a patterned long-hair rug.
Typically, the inter-thread sizing of the grid utilized in latch or rug hooking is in the range of 4 to 6 threads per inch. The diameter or cross-sectional thickness of the yarn or the like is selected to substantially conform with the dimensions of the openings or interstices defined between adjacently positioned threads in the grid.
This general correspondence of the yarn diameter and the interstice sizing is necessary to enable effective retention of the yarn on the threads. Inasmuch as each length of yarn is not knotted or tied but merely wound about the thread and thence through its own loop, it is subject to loosening and slippage and consequently to being inadvertently pulled from the grid, leaving an obvious discontinuity or hole in the completed design.
By utilizing relatively thick yarn, each interstice in the grid is substantially filled with the ambient fibrous material of the yarn. The fibrils of adjacently positioned lengths of the yarn frictionally intermesh and interengage with one another to facilitate the retention of the yarn on the threads. In addition, the use of relatively thick yarn provides a particularly dense pile and accordingly contributes to greater continuity in the completed design. As a consequence of the relatively large size of each of the interstices, a grid of substantial overall size is generally required to accommodate a complete picture or design.
It has been found that more attractive patterns and designs can be effected by utilizing latch hooking techniques on needlepoint size surfaces and designs. To do so requires a reduction in the overall size of the grid, a decrease in the space between adjacent threads, as well as a corresponding reduction in the cross-sectional diameter or thickness of the yarn utilized. A smaller latching tool is also required to fit into the interstices. A significant problem, however, arises when the latch hooking procedure is attempted with such reduced-size materials, and more specifically with a spacing between adjacent grid threads that is less than or equal to one-tenth of an inch (ten or more threads per inch).
In particular, it is found that the yarn is no longer adequately retained on the threads. The least application--inadvertent or otherwise--of a pulling force on an outwardly extending end of a thread-engaging piece of yarn causes longitudinal slipping movement of the yarn relative to the thread about which it is wound. The latch hooking method of attachment fails to provide effective retained engagement of the yarn on the threads in the reduced-scale use.
The present invention is based upon a recognition that this lack of positive retention results from the necessity of correspondingly reducing the thickness of the yarn to conform to the reduced size of the grid interstices. Because the yarn used is significantly thinner, it has a substantially smaller circumference and, therefore, many less fibrils for intermeshing and interengagement with the fibrils of adjacently positioned pieces of yarn. Consequently, there is little frictional interaction between adjacent pieces of yarn to facilitate the retention of the same about the threads, and the yarn therefore slips or slides easily thereabout.
It is, therefore, the desideratum of the present invention to enable the application of latch hooking techniques on needlepoint-type and sized supports and to provide for increased non-slip retention of the fibrous material about the threads of the support grid when the fibrous material is engaged about the threads using a latch hooking procedure.